24/7 G2 Front Sight

Does anyone know the size hex wrench required to remove the front sight and where to get one? I was able to find a .050" (1.3 mm?) and a .061" (1/16") key. The .050" is too small and turns in the socket and the .061" won't fit at all. Guessing it needs a 1.4mm (.055") key but can't seem to find one.

Any help would be appreciated.

Thanks.